Fluid channel divider



Nov. 1, 1966 P. BAUER 3,282,297

' FLUID CHANNEL DIVIDER Filed July 30, .1964

FIG. 1

F IG 2 22\ 40 22 18 F |G 3 g I 60" 62 as as INVENTOR PETER BAUER ATTORNE YS United States Patent 3,282,297 FLUID CHANNEL DIVIDER Peter Bauer, Germantown, Md., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed July 30, 1964, Ser. No. 386,158 12 Claims. (Cl. 13839) The present invention relates to fluid channel means for dividing a fluid stream or signal into a plurality of parts without loss of quality in the signal transmission.

The rapidly developing field of pure fluid amplifier techniques has found particular application in computer and data processing logic circuits wherein information is transmitted by a fluid medium rather than by an electric voltage or current. In the basic pure fluid amplifier of the prior art, a fluid power jet stream of relatively large energy is deflected into one of several output channels by means of a smaller energy control stream which impinges thereon at about a right angle. Quite often, the power :stream in the selected output channel is required to drive two or more other fluid amplifiers by dividing the output power stream into plural portions each of which is utilized as a control stream input to a said different further fluid amplifier. However, because of the relative miniaturization of pure fluid systems (e.g., the power jet cross sectional flow area is sometimes on the order of 0.020" X 0.125" for rectangular channel design), it is important to prevent any separation of the flowing fluid from the channel walls at the dividing point in order to maintain quality signal transmission. It is especially necessary to avoid any significant pressure pulse propagation delay in the divider device, since where logical operations are to be performed on a plurality of fluid signals, their exact timing in the system is of utmost importance in order that all information will arrive at a logic circuit at the same time. Furthermore, it is necessary that attenuation of fluid signals be held to a minimum so that an output power stream can drive a maximum number of loads.

The present invention is concerned with dividing a fluid stream or signal in a present day pure fluid logic system into a plurality of portions, either of equal size or in a specific ratio, with minimum attenuation and propagation delay thereof. In general, the invention comprises an entrance or input channel in which full fluid flow exists from an input flow area to preferably a slightly smaller output flow area, there being a sharp divider tip assembly at said output flow area which divides the fluid into at least two output fluid streams. Each output fluid stream flows in a different exit or output channel which in turn is dimensioned relative to the entrance channel of the device in order to prevent separation of the fluid from any of the channel walls, i.e., to prevent partial channel flow.

It is therefore one object of the present invention to provide a fluid channel divider for dividing a fluid signal in a manner to thereby maintain quality signal transmission.

Another object of the present invention is to provide means for dividing a flowing fluid signal or stream into equal parts whereby full channel flow is maintained throughout the flow length.

A further object of the present invention is to provide a fluid channel divider for dividing a fluid signal into at least two parts without introducing excessive propagation delay or excessive attenuation.

These and other objects of the present invention will become apparent during the course of the following description, to be read in view of the drawings, in which:

FIGURE 1 is a plan view of the fluid channel divider;

FIGURE 2 is a side elevation view of the fluid channel divider; and

FIGURE 3 is an end elevation view in section of the fluid channel divider.

Referring now to the figures, there is shown a preferred embodiment of the invention in which a fluid stream travelling in the direction of the arrows is divided into two equal parts in a fluid channel divider having a rectangular cross-section. An entrance or input channel 10 and two exit or output channels 12 and 14 preferably have side walls formed in a central body 16 made of plastic or other fluid impervious material. Parallel plastic cover plates 18 and 20 form the top and bottom walls, respectively, of the fluid channels and are fastened to body 16 by means of threaded screws 22 at the corners thereof. This illustrated embodiment may be thought of as two dimensional" since the depth of any channel remains constant throughout its length, with only the channel width varying as hereinafter described.

The outer side walls 24 and 26 of exit channels 12 and 14, respectively, are smoothly joined at points 28 and 30 without abrupt changes in contour to the side walls 32 and 34, respectively, of entrance channel 10. The inner side walls 36 and 38 of the output channels 12 and 14 come together to form an extremely sharp knife edge divider tip 40 which faces upstream. The sharpness of tip 40 contributes in maintaining full channel flow as the fluid is divided.

Dash line rectangle 42 encloses a critical region in which fluid impinging against divider tip 40 normally tends to separate from the channel walls in prior art devices. For subsonic jet flow at velocities which are large fractions of the speed of sound (as usually needed for digital handling devices), region 42 normally extends from a distance immediately upstream from tip 40, to a distance downstream therefrom which in turn may be equal from around one to two times the plan view width of channel 10 at tip 40. In order to prevent both the said separation of signal flow and also the creation of excessive turbulence in this critical region (which would attenuate the output fluid signals as well as increase their propagation time through the output channels), the entrance channel 10 output flow area 54 at divider tip 40 (said flow area 54 being made up of the sum of the input flow areas 50 and 52 of channels 12 and 14, respectively, at a point immediately adjacent to divider tip 40) should preferably be slightly less than a flow area 55 of channel 10 found immediately upstream from divider tip 40 and region 42. In other words, entrance channel should smoothly and ever so gradually converge toward divider tip 40, either along its entire length from its inlet flow area 32 as shown, or alternatively beginning, at least from said upstream flow area 55. In this way is overcome any tendency of the fluid to separatefrom the channel walls upon making contact with tip 40. Also necessary to the desired operation of this device is that any gross side wall divergence in the exit channels, from flow areas equal to their input crosssectional flow areas 50 and 52, be commenced at about points 56 and 58 or, in other words, at points which are downstream from the critical fluid region 42 a suflicient distance so as not to be in an influencing proximity there to. This side wall divergence in each output channel should be both gradual and even, such that there are no abrupt change-s in side wall curvature or contour in order to insure adherence of the fluid to the side walls at all times.

The particular embodiment of the invention shown herein has its exit channels 12 and 14 finally diverging to respective output flow areas 44 and 46 each about equal to the input flow area 48 of entrance channel 10 so as to permit use of the same diameter tubing for conlast defined relationship is not essential to the operation necting the fluid divider into a system. However, this of the present invention. Furthermore, although the top and bottomwalls of the output channels are shown in the present embodiment to be parallel throughout their length (as are the top and bottom walls of input channel the same criteria of gradual and even divergence would also apply were the device constructed in three dimensional form, as for example, with circular cross section Where channel depth also varies. The side, top, and bottom walls of input channel 10 in any such three dimensional embodiment also should not have abrupt changes in contour or direction so that the full channel flow of the fluid therein will 'be insured as it approaches the output cross-sectional area 54. In other words, at no time should there be partial channel fluid flow in any of the divider channels. All channel walls in any embodiment should have completely smooth surfaces.

To further insure that there will be no flow separation from the exit channel walls in proximity of the critical region 42, which would otherwise cause increased propagation delay, each exit channel flow area may be slightly decreased to a value below its respective input area value 50/52 at about points 60 and 62 which in turn are immediately downstream from said critical region 42 but upstream from said points 56 and 58 where the exit channel sidewalls commence to diverge from flow areas equal to their input flow areas 50/52. Thus, each exit channel in this case has a gradually converging sidewall contour from divider tip 40 to point 60/62, then a gradually diverging side wall contour from point 60/ 62 to its outlet. The extremely gradual convergence of the output channel side walls to points 60 and 62 is such that no voids will occur in the fluid.

What has been shown and described is a pure fluid channel divider configuration for dividing a fluid stream into plural parts without creation of partial channel flow conditions, thus resulting in minimum delay and low attenuation. If the described criteria are observed, essentially sonic signal propagation speeds through the divider may be achieved (maximum possible) without gross signal waveform distortion (degradation). Of course, a division of the fluid energy into two or more parts is natural. Although the preferred embodiment discloses rectangular fluid channels, the invention is not limited to this par ticular cross-sectional shape. Furthermore, additional output channels might be provided as long as the above relationships are maintained. Therefore, many modifications and alterations will be apparent to those skilled in the art without departure from the spirit of the invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A fluid channel divider which comprises:

(a) an entrance fluid channel with an input flow area at one end for receiving a fluid stream, a slightly smaller output flow area at its opposite end, and a wall surface therebetween without abrupt changes in contour so as to insure full channel flow throughout its length;

(b) sharp divider tip means located at said entrance channel opposite end and facing upstream for dividing said entrance channel output flow area into a plural number N of smaller output flow areas; and

(c) a plural number N of exit fluid channels without abrupt changes in wall contour, each having one end thereof smoothly and unabruptly joined both to said entrance channel opposite end and to said divider tip means such that each exit channel input flow area is coextensive with a different one of the said entrance channel smaller output flow areas, and wherein a critical region, in which fluid tends to separate from channel walls, extends immediately upstream and downstream from said divider tip means; with each exit fluid channel further commencing, at a first point downstream and spaced apart from said critical region, to gradually diverge from a flow area equal to its own said input flow area towards a larger output flow area at its opposite end.

2. A fluid channel divider according to claim 1 wherein each said exit fluid channel is slightly reduced in flow area below its input flow area at a second point immediately downstream from said critical fluid region but upstream from said first point.

3. A fluid channel divider according to claim 1 where said entrance channel smaller output flow areas are of equal size.

4. A fluid channel divider which comprises:

(a) an entrance fluid channel with an input flow area at one end for receiving a fluid stream, a slightly smaller output flow area at its opposite end, and a wall surface therebetween without abrupt changes in contour so as to insure full channel flow throughout its length;

('b) sharp divider tip means located at said entrance channel opposite end and facing upstream for dividing said entrance channel output flow area into a plural number N of equal smaller output flow areas; and

(c) a plural number N of exit fluid channels without abrupt changes in Wall contour, each having one end thereof smoothly and unabruptly joined both to said entrance channel opposite end and to said divider tip means such that each exit channel input flow area is coextensive with a different one of said entrance channel smaller output flow areas, and wherein a critical region, in which fluid tends to separate from channel walls, extends both immediately upstream and downstream from said divider tip means; with each exit fluid channel having a gradually converging wall contour from said divider tip means to a first point immediately downstream from said critical fluid region and a gradually diverging wall contour from said first point to its opposite end.

5. A fluid channel divider which comprises:

(a) an entrance fluid channel with an input flow area at one end for receiving a fluid stream, a slightly smaller output flow area at its opposite end, and a wall surface therebetween without abrupt changes in contour so as to insure full channel flow throughout its length;

(b) sharp divider tip means located at said entrance channel opposite end and facing upstream for dividing said entrance channel output flow area into two smaller output flow areas; and

(0) two exit fluid channels without abrupt changes in wall contour, each having one end thereof smoothly and unabruptly joined both to said entrance channel opposite end and to said divider tip means such that each exit channel input flow area is coextensive with a different one of the said entrance channel smaller output flow areas, and wherein a critical region, in which fluid tends to separate from channel walls, extends both immediately upstream and downstream from said divider tip means;with each exit fluid channel further commencing at a first point downstream and spaced apart from said critical region, to gradually diverge from a flow area equal to its own said input flow area towards a larger output flow area at its opposite end.

6. A fluid channel divider according to claim 5 wherein each said exit fluid channel is slightly reduced in flow area below its input flow area at a second point immediately downstream from said critical fluid region but upstream from said first point.

7. A fluid channel divider according to claim 5 where said entrance channel smaller output flow areas are of equal size.

8. A fluid channel divider which comprises:

(a) an entrance fluid channel with an input flow area at one end for receiving a fluid stream, a slightly smaller output flow area at its opposite end, and a wall surface therebetween without abrupt changes in contour so as to insure full channel flow throughout its length;

(b) sharp divider tip means located at said entrance channel opposite end and facing upstream for dividing said entrance channel output flow area into two equal smaller output flow areas; and

(0) two exit fluid channels without abrupt changes in wall contour, each having one end thereof smoothly and unabruptly joined both to said entrance channel opposite end and to said divider tip means such that each exit channel input flow area is coextensive with a dilferent one of said entrance channel smaller output flow areas, and wherein a critical region, in which fluid tends to separate from channel walls, extends both immediately upstream and downstream from said divider tip means; with each exit fluid channel having a gradually converging wall contour from said divider tip means to a first point immediately downstream from said critical fluid region and a gradually diverging wall contour from said first point to its opposite end.

9. A fluid channel divider which comprises:

(a) an entrance fluid channel having a rectangular cross-section and comprised of spaced apart side walls and parallel spaced apart top and bottom walls all of which are Without abrupt changes in contour so as to permit full channel flow therethrough, and with an input flow area at one end for receiving a fluid stream and a slightly smaller output flow area at its opposite end; and

(b) first and second exit fluid channels branching from said entrance channel opposite end, each exit channel having a rectangular cross-section and being comprised of spaced apart side walls and parallel spaced apart top and bottom walls all of which are without abrupt changes in contour, where the top and bottom walls of each exit channel are smoothly and unabruptly joined to the top and bottom walls, respectively, of said entrance channel, and one side wall of each exit channel is smoothly and unabruptly joined to a difi'erent side wall of said entrance channel while the other side walls of said exit channels come together at said entrance channel output flow area to form a sharp divider knife edge facing upstream for dividing said entrance channel output flow area into two smaller output flow areas such that a critical region, in which fluid tends to separate from the channel walls, extends both immediately upstream and downstream from said divider knife edge, with the side walls of each said exit fluid channel further commencing, at a first point downstream and spaced apart from said critical region, to gradually diverge from aflow area equal to its own input flow area towards a larger output flow area at its opposite end.

10. A fluid channel divider according to claim 9 where said entrance channel smaller output flow areas are of equal size.

11. A fluid channel divider according to claim 9 wherein each said exit fluid channel is slightly reduced in flow area below its input flow area at a second point immediately downstream from said critical fluid region but upstream from said first point.

12. A fluid channel divider according to claim 11 where said entrance channel smaller output flow areas are of equal size.

References Cited by the Examiner UNITED STATES PATENTS 1,905,733 5/1933 Moore 137-815 3,187,763 6/1965 Adams l378l.5 3,238,961 3/1966 Hatch 13781.5

M. CARY NELSON, Primary Examiner. W. CLINE, Examiner. 

1. A FLUID CHANNEL DIVIDER WHICH COMPRISES: (A) AN ENTRANCE FLUID CHANNEL WITH AN INPUT FLOW AREA AT ONE END FOR RECEIVING A FLUID STREAM, A SLIGHTLY SMALLER OUTPUT FLOW AREA AT ITS OPPOSITE END, AND A WALL SURFACE THEREBETWEEN WITHOUT ABRUPT CHANGES IN CONTOUR SO AS TO INSURE FULL CHANNEL FLOW THROUGHOUT ITS LENGTH; (B) SHARP DIVIDER TIP MEANS LOCATED AT SAID ENTRANCE CHANNEL OPPOSITE END AND FACING UPSTREAM FOR DIVIDING SAID ENTRANCE CHANNEL OUTPUT FLOW AREA INTO A PLURAL NUMBER N OF SMALLER OUTPUT FLOW AREAS; AND (C) A PLURAL NUMBER N OF EXIT FLUID CHANNELS WITHOUT ABRUPT CHANGES IN WALL CONTOUR, EAHC HAVING ONE END THEROF SMOOTHLY AND UNABRUPTLY JOINED BOTH TO SAID ENTRANCE CHANNEL OPPOSITE END AND TO SAID DIVIDER TIP MEANS SUCH THAT EACH EXIT CHANNEL INPUT FLOW AREA IS COEXTENSIVE WITH A DIFFERENT ONE OF THE SAID ENTRANCE CHANNEL SMALLER OUTPUT FLOW AREAS, AND WHEREIN A CRITICAL REGION, IN WHICH FLUID TENDS TO SEPARATE FROM CHANNEL WALLS, EXTENDS IMMEDIATELY UPSTREAM AND DOWNSTREAM FROM SAID DIVIDER TIP MEANS; WITH EACH EXIT FLUID CHANNEL FURTHER COMMENCING, AT A FIRST POINT DOWNSTREAM AND SPACED APART FROM SAID CRITICAL REGION, TO GRADUALLY DIVERGE FROM A FLOW AREA EQUAL TO ITS OWN SAID INPUT FLOW AREA TOWARDS A LARGER OUTPUT FLOW AREA AT ITS OPPOSITE END. 